Unknown, 1625 c.+25
Louwman Collection of Historic Telescopes Arrow right Arrow left

photo - whole telescope
Basic Info

Maker: Unknown

Year: 1625 c.+25

Year Range: -

Year Notes:

Manufacturing Location: France [?]


Signature Notes:


No stand present.

Collection: Louwman Collection of Historic Telescopes

Accession #: LC 17


Tiemen Cocquyt, "400 Years of Telescopes" booklet, Zeeuws Museum, 2008. Item 31.

Louwman, P.J.K. and Zuidervaart, H.J., "A Certain Instrument for Seeing Far: Four Centuries of Styling the Telescope Illustrated by a Selection of Treasures from the Louwman Collection of Historic Telescopes". Wassenaar, 2013. p. 57.

Bolt, M. and Korey, M. "The world's oldest telescopes." THE ORIGINS OF THE TELESCOPE. Eds. Albert Van Helden, Sven Dupré, Rob van Gent, and Huib Zuidervaart. Amsterdam: Knaw Press. 2010. p. 247-8.

Public Notes:

"Two-draw telescope made of curved African ivory fluted lengthwise.
With the remains of marble paper on the drawtubes.
Length 13.2-21 cm, Ø 1.8-2.2 cm. Convex objective lens Ø 1.5 cm
with focal length of 27.4 cm. Concave eye lens. Magnification 4 times (in diameter).
Unsigned. Presumably first quarter of the seventeenth century.

According to Stuart Talbot (2008) the shape, length and optics of this telescope indicates a very early date. The construction resembles the narrow slightly conical telescope in the 1614-portrait of Simon Marius. Such ivory telescopes were made for the seventeenth century cabinets of curiosities. It is remarkable that the turning tables which were used for the turning of ivory resemble the mechanical machines that were developed in the seventeenth century for the grinding of telescope lenses. It probably was no coincidence that the English ‘ivory turner’ Richard Reeve(s) developed himself into one of the first optical instrument makers in England. In the Netherlands, in the 1630s, Descartes and Constantijn Huygens Senior also ordered telescope lenses at an unnamed "Tourneur d’Amsterdam"" (Louwman, and Zuidervaart, 2013. p.36).

Length (open): 132

Length (closed): 210


Exit pupil:

Object status:

Optical Basics

Objective type: singlet

Optical style

Physical style spyglass

Functional style

Materials: ivory

Optical/Lab Data

Drawtube data:

Drawtube notes:

Objective Data

CA curvature (diopters): CB curvature (diopters): PD lens power (diopters): fD focal length (mm): t thickness (mm): free aperture (mm): full aperture (mm): nD refractive index: ν Abbe No.:
Lens 1 274.00 22.00